Method of manufacturing closed-link brake hangers



Ot. 6,. 1931. F. SCHAEFER 1,326,027

METHOD OF MANUFACTURING CLOSED LINK BRAKE HANGERS Filed April 21, 1930 l i i.

WITNESS Patented Get. 6, 1931 PATENT oFricE FREDERIC SCI-IAEFER, OF PITTSBURGH, PENNSYLVANIA METHOD OF MANUFACTURING CLOSED-LINK BRAKE HANGERS Application filed April 21,

The invention relates to the manufacture of closed link or loopbrake hangers for supporting the brake beams of brake rigging on railway car trucks, the object being to improve the method of manufacturing such brake hangers disclosed in my Patent No. 1,716,933 to the end that the resulting hangers will have greater strength where their horizontal yokes or arms join their Vertical sides.

The invention is illustrated in the accompanying drawings, of which Fig. 1 is a plan view of a rough blank from which a closed link brake hanger is forged; Fig. 2 a plan view of a hanger blank forged from the rough blank of Fig. 1, the blank being shown in full lines as being engaged by expanding tools, and in dottedlines after being expanded; Fig. 3 a plan view of the finished hanger; Fig. a longitudinal centralsection of the lower portion of the hanger showing the appearance of its fiber structure when etched; 5 a view, corresponding to Fig. 4, of the lower portion of a brake hanger made ac cording to the method disclosed in my said patent; and Fig. 6 a detail sectional view taken on the line vVIVI, Fig. 3. v

In the actual manufacture of brake hangers according to the method of my said patent, an elongate rolled steel blank is first forged to form a brake hanger blank of parallelogram shape having ends for forming hanger yokes, and sides for forming hanger arms disposed at obtuse and acute angles to the ends, the form of the blank being such that its extremities are at two corners of the finished hanger where the yokes join with the side arms. These hanger blanks have been so forged from the. rolled steel blanks that the elongated fibers of the steel, produced by rolling of the metal, extend longitudinally in the side members of the hanger blanks. In testing brake hangers so formed it has been found that they first fail at the corners which are the extremities of the original parallelogram blanks. In this connection it will be understood that the corners of closed link brake hangers are the points where the hangers are subjected to maximum stresses, the loads being there transmitted from the hori- 1930. Serial No. 445,899.

zontal yokes to the vertical side arms by combined tension and bending stresses.

In seeking to determine the cause of the above explained test failures of these brake hangers, I cut several of the hangers in their central longitudinal planes and etched their cut surfaces. This showed that the elongated fibers of the steel, produced by the rolling of the original blank, extend in the manner illustrated in Fig. 5, which illustrates one of the etched sections. As there shown, the fibers 1 and 2 of the side arms 3 and 4 extend longitudinally of these arms, and the fibers 5 of horizontal yoke 6. extend substantially longitudinally of such yoke. At the junction between arm 4 and yoke 6 the fibers follow the curvature of the metal, whereas at the junction between yoke 6 and side 3 the fibers turn to the general direction indicated by the dot and dash line 7. Accordingly, at this corner of the hanger, which is one of the extremities of the original hanger blank, the fibers extend transversely of the center line of the hanger. I have discovered thatthis disposition of the fibers of the steel at the corners of the hangers which were the extremities of the original forged hanger blank is the cause of the test failure of the hangers at these particular corners.

In the practice of the invention herein dis closed, a hanger blank is first forged from a blank of unidirectional rolled steel, by which is meant a rod or bar of suitable cross section which has been rolled in one direction a, as distinguished from beingrolled part of the time in one direction and part of the time at right angles thereto. The hanger blank is so forged from the rolled steel that the former has spaced parallel sides which later form the side arms of the hanger, in which sides the fibers of the steel extend longitudinally, and that it has outwardly-extending yoke-forming ends in the extremities of which, intermediate of the junctures of these ends with the side arms, the fibers of the steel extend transversely. After thus forging the blank. the parallel sides are spread laterally to straighten the ends so that they form the parallel yokes of the hanger. In this 0peration, the ends are also preferably stretched somewhat, with the attending ad antages explained in my said patent. Subsequently the side arms are preferably stretched, with like advantages.

In the accompanying drawings, the invention is illustrated in its applicability to the manufacture of a loop or closed link brake hanger provided with an eye, although it is obvious that a simple loop or closed link brake hanger may be manufactured in the same way by the mere omission of the eye and the stem connecting it to one of the yokes. In the first step of the procedure, a heated blank 10, which may be round, rectangular, or of other suitable cross sectional shape, is forged to form the hanger blank of Fig. 2 having, when the forging flash has been trimmed, parallel sides 11 and 12, and outwardly-extending yoke-forming ends 12-) and 14. \Vhile the outwardly-extending ends may be of various forms, they are preferably curved throughout, as shown, and are preferably symmetrical about the longitudinal center of the blank. In this forging operation. sides 11 and 12 and ends 13 and 14.- are preferably forged to their final cross sectional shapes, the sides preferably being round, and the ends, particularly the lower yokcforming end, being of elongated cross-section, such for example as shown in Fig. 6. As illustrated, the yoke-forming ends 13 and 1 1 and the ends of sides 11 and 12 adjoining them have cross-sectional areas somewhat greater than that of the main portions of the sides, thus increasing the strength of the yokes and providing excess metal to compensate for subsequent wear while in service.

After the blank has been thus forged, and the forging flash trimmed from it, its sides are engaged by suitable expanding tools 15, placed in the open slot between the sides, and spread laterally to straighten the yoke-forming ends and to stretch them, the thus spread blank being indicated in dotted lines in Fig. 2. Thereafter the yoke ends 13 and 14 of the hanger are similarly engaged and slightly spread apart to stretch sides 11 and 12 and to positively position the endsparallel to each other.

In forming the original blank of Fig. 3 for a loop hanger provided with an eye, the blank is forged to have the eye 16 connected to yokeforming end 14 by a stem 17, the eye lyin in the plane of the sides and arms of the blank. Subsequently, the stem is twisted on its longi tudinal axis to cause the eye to lie in a plane perpendicular to that of the sides and ends, as shown in Fig. 3. As will be seen, stem 17 is thickened and correspondingly strengthcned where it joins end 14. By thus originally forming the eye in the plane of-the hanger sides and ends or yokes, there results substantial economies in manufacture, and the eye may be easily shaped to its desired final form.

Specifically, the pin-receiving holes of the eye may be formed in the original forging operation, making it unnecessary to have a second forging operation for this purpose, or to later drill an opening in the eye, and also the faces of the eye may be forged parallel to each other.

In Fig. 4 there is shown an etched face of the lower end or yoke of a brake hanger inanufactured according to this invention, and cut in the central longitudinal plane of its sides and yokes. As there illustrated, the fibers 20 and 21 of the steel in side arms 11 and 12 extend longitudinally of such arms, and where the side arms join end or yoke 13, the fibers of the steel follow the general line of curvature of the metal. Intermediate of the ends of yoke 13, the fibers turn downwardly and extend transversely of the yoke in the direction indicated by the dot and dash line 22. As will be observed, this intermediate portion of the yoke is the lower extremity of the blank of Fig. 2.

In tests made upon brake hangers manufactured according to this invention, it has been found that the hangers do not first fail at their corners where maximum stress conditions prevail, and that by reason of this the hangers so manufactured are materially stronger than those made according to the method disclosed in my said patent.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention, and have illastrated and described the preferred manner of practicing it. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim as my invention:

1. The method of manufacturing a closed link brake hanger, comprising forging from a blank of unidirectiomil rolled steel an elongate hanger blank having spaced parallel hanger sides in which the fibers of the steel extend longitudinally and having outwardlyextending yokeforming ends in the extremities of which the fibers of the steel extend transversely, and spreading said sides laterally to straighten said ends.

2. The method of manufacturing a closed link brake hanger, comprising forging from a blank of unidirectional rolled steel an elongate hanger blank having spaced parallel hanger sides in which the fibers of the steel extend longitudinally and having outwardly extending yoke-forming symmetrical ends in the extremities of which the fibers of the steel extend transversely, and spreading said sides laterally to straighten said ends.

3. The method of manufacturing a closed link brake hanger, comprising forging from a blank of imidinectional rolled steel an elongate hanger blank having spaced parallel hanger sides in which the fibers of the steel extend longitudinally and having outwardlyextending yoke-forming ends in the extremities of which the fibers of the steel extend transversely, spreading said sides laterally to straighten said ends, and finally spreading said ends to stretch said sides and to bring the ends into parallelism.

4. The method of manufacturing an eye and loop brake hanger, comprising forging a body of metal to form a hanger blank having oppositely disposed sides and ends and having a stem connected to one of said ends and an eye at the outer end of the stem lying in the plane of said sides and ends, and subsequently twisting said stem on its axis to cause said eye to lie in a plane perpendicular to that of said sides and ends.

In testimony whereof, I sign my name FREDERIC SOHAEFER. 

